If you convert the money this year and your tax situation changes, you’ll have an opportunity for a do-over. You have until October 15, 2018, to undo a conversion you made in 2017, a process called recharacterization. The money returns to the traditional IRA and you get back the taxes you paid on the conversion (or avoid having to pay the tax bill if you undo the conversion before you file your return). If congressional action means you’re in a lower tax bracket next year so the conversion would cost you less, you can reconvert the account in 2018.

“If there’s any chance the Roth conversion makes sense, I’d make it now,” says Jeffrey Levine, CEO and director of financial planning for the BluePrint Wealth Alliance in Garden City, N.Y. If it turns out not to be a good move because of a change in the tax law, a market decline or whatever reason, he says, then you can recharacterize.